1. Field of the Invention
The present invention relates to an apparatus for automated handling of loads fastened to load suspension means of a handling appliance. More particularly, the present invention relates to an apparatus for automated handling of ISO containers, by means of a spreader.
2. Description of the Related Art
German reference 1 556 324 discloses a generic type of spreader for handling containers. The aim of the known design is to provide an apparatus for picking up the containers that engages the corresponding locking parts of the container even if the container is on uneven ground or is somehow twisted or distorted. To this end, various measures are proposed, including connecting the spreader to the lifting yoke by pendulum support. The pendulum supports are designed so as to be axially displaceable relative to the lifting yoke. German reference 1556 324 also teaches a flexible connection to ensure that the spreader can be better adapted to the container.
Automated container terminals are known using various load suspension means. The design of these is dependent upon special conditions existing in each case at these terminals and cannot be transferred to other terminals. The spreaders, likewise equipped with lifting yokes, have the disadvantage of either a high dead weight or a large overall height. In normal container terminals having stacking heights of three or four meters, every additional meter in height of a crane runway support involves progressively rising costs for the terminal. In addition, the known lifting yokes also entail considerable design and manufacturing costs, which it is desirable to reduce.
The object of the present invention is to provide an apparatus for use in handling appliances, i.e., for picking up and setting down ISO containers so that it is possible to automate handling of the load. This is required for automatic use of, for example, a container stacking crane.
The present invention uses a generic type of lifting yoke on the spreader and ensures safe and automatic use of the spreader, while being designed in a simple, functionally reliable and cost saving manner.
To achieve the object, the generic type apparatus is improved because the lifting mechanism is part of a rigid load guide. A cylinder part is linked between the lifting mechanism and the lifting yoke both as a torque support and for displacement and pivoting of the lifting yoke relative to the load guide. Sensors are provided in the cylinder pair so that the relative orientation of the lifting yoke with respect to the spreader and/or to the load guide can be detected in each position.
The apparatus of the present invention uses a handling appliance having a rigid load guide which can absorb horizontal forces that occur during handling of the load. Rigid load guides include, for example, rope zones of a crane trolley, quadruple frame guides of straddle carriers or vertical guides of a beam in a container stacking crane. Cylinder pairs are arranged between the load guide and the lifting yoke permitting a length and angular adjustment of the lifting yoke relative to the load guide and also permitting a horizontal movement and a tilting movement of the lifting yoke in the transverse and longitudinal directions. All the movements of the lifting yoke are detected and indicated or processed by a sensor system.
Preferably, the cylinder pair is arranged so that the two piston/cylinder units describe the sides of an isosceles triangle, at least when the pair is in the retracted state. Both cylinders are linked to the lifting yoke in the region of the tip of the isosceles triangle. The opposite ends of the piston/cylinder units are fastened in an articulated manner in a common horizontal plane on both sides of the load guide. In this way, the cylinder pairs can also act as a torque support, the fixed points of which consist of two spherical plain bearings on the load guide and one pivoting bearing pair on the lifting yoke. The cylinder pairs are preferably actuated via a central hydraulic system, to allow for correction of the rotary and longitudinal axis for fine positioning of the spreader for the container or containers relative to the aiming point, (i.e., truck loading frame). Fine positioning of the lifting yoke in the transverse direction is preferably effected with the crane trolley travel of the handling appliance.
According to a preferred embodiment of the present invention, the cylinder pair consists of double acting individual cylinders which are firmly connected to one another at their base flanges. This permits favorable control of the individual cylinders.
In a more preferred embodiment of the present invention, the load guide is formed by the vertically guided guide column of a corresponding handling appliance. The lifting yoke is supported in its transverse direction on the guide column by means of a guide running in the longitudinal direction of the yoke. As a result, the lifting yoke is fixed relative to the guide column in the transverse direction, i.e., in the travel direction of the trolley, whereas a displacement is possible in the longitudinal direction.
According to a further embodiment of the present invention, the guide is preferably designed as a guide rail for a running roller, which is arranged at the front end of the guide roller, is rotatable about a horizontal axis, and is assigned to lateral supporting rollers which can roll on the flanks of the guide rail. The running surfaces of the running roller and d of the supporting rollers are of crowned design. Thus, the running rail running in the center of the lifting yoke and the supporting roller unit, together with the horizontally acting running roller and the two smaller, symmetrically arranged guide rollers, form the bearing point of the guide column. The crowned design of the running surfaces serves to permit rotation of the lifting yoke relative to the guide column. A displacement of the lifting yoke relative to the guide column by about xc2x1500 mm is possible in the longitudinal direction of the lifting yoke, i.e., in the travel direction of the bridge. The apparatus according to the present invention permits pivoting of about xc2x15xc2x0 about the rotary axis of the guide column, i.e., about its longitudinal axis.
The cylinder pairs are fastened on both sides of the guide column and enable the apparatus according to the present invention to be put into a defined zero position after the spreader has been lifted.
The spreader may be connected to the lifting yoke, for example, via four pendulum supports. According to a still further embodiment of the present invention, piston/cylinder units are arranged essentially horizontally while being oriented transversely between the lifting yoke and spreader. The cylinder spaces of the piston/cylinder units can be operated so as to be unpressurized when the spreader is being set down on the container. As such, the piston/cylinder units can act as fixing and damper elements. One end of the respective cylinder pairs is connected to the lifting yoke by spherical plain bearings, whereas the other end is mounted on the spreader. In a preferred embodiment, three cylinder pairs are used with two being arranged in the travel direction of the trolley near the suspension points of the pendulum supports. The other cylinder pair is located in the travel direction of the bridge centrally in the direction of the spreader longitudinal axis.
Depending on the wind force acting on the load, the movement can be damped by specific hydraulic pressure in the cylinder pairs. The relative movement between the lifting yoke and the spreader as a reaction to placement of the spreader on the container or containers on the aiming point is made possible by free operation of the cylinder pairs. The horizontal adjusting travel of the spreader axes in the longitudinal and transverse directions is xc2x1200 mm for each axis; this is ensured by the mechanical end positions of the piston and piston rods of the respective cylinder pairs.
In addition, a mechanical stop may be provided between the lifting yoke and spreader to limit the vertical clearance space between the components. This clearance space should preferably be about 200 mm between the lifting yoke and spreader. The mechanical stop comes into effect after an approximately 210 mm vertical stroke and is dimensioned so that the weight of the lifting yoke and guide column is absorbed in a statically safe manner. The stop also serves as a rest for the lifting yoke on the spreader when the two parts are transported together.
In a further embodiment of the present invention, the complete hydraulic unit, the electrical control and the data communication of both the spreader and the lifting yoke are arranged on the spreader. All the hydraulic cylinders are supplied from the power pack of the spreader. Quick release couplings for the hydraulic hoses and plugs for the cable connections form a clear and universal interface. This ensures rapid and simple exchange of the spreader, even in the case of different makes.
All the orientations of the spreader relative to the lifting yoke can be electronically detected and evaluated. To this end, the spreader is equipped with all the sensors necessary for automatic operation. These sensors electronically detect and signal all the positions of the spreader and feed them to the evaluating means. These detected positions also include the inclination and tilt of the spreader in the bridge and trolley travel direction during delivery and lifting of the container.
The orientation of the spreader in the bridge and trolley travel direction is preferably detected via the movement of the pendulum supports relative to the suspension in the lifting yoke. To this end, an elastic stop is provided on the spreader below the pendulum support mounting, so that the pendulum rod cannot slip through in the unloaded state. As a result, a relative movement occurs between the top end of the pendulum support and the lifting yoke when the spreader moves relative to the lifting yoke. This vertical relative movement is detected as a signal and evaluated.
In addition, for antirotation locking of the ropes connected to the lifting yoke in the region of its corner points, the rope ends are accommodated in parallelpiped like rope connections. An adjusting device in the form of intermediate shims (for compensating for the lifting rope length) is provided at each rope.
The present invention can supplement conventional spreaders in such a way as to automate them. The manufacturing costs of the present invention are relatively low with the cost for the apparatus and the bearing points on the spreader being slight.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings, It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.